Brief History

Masuyama castle (増山城) is located at a hill of 120 meter height above sea level, in the mountainous area which separates Toyami plain and Toyama plain. Historically Hokuriku kaido way, the main road from Kyoto city toward Hokuriku region, passes Kurikaratoge path at the border of Kaga province (Ishikawa prefecture) and Ecchu province (Toyama prefecture) and downs to the Toyama bay along with Shokawa river and continues to Toyama area along the coast. But there was also a direct way which passes hilly area from current Tonami city to Toyama city. Masuyama castle is located at a hill guarded by winding river and close to this direct way, and it is a suitable place both for governance and defense. Masuyama castle is a large castle and regarded as one of three major mountain castles of Ecchu province along with Moriyama castle near Noto peninsula and Matsukura castle in Uozu area.

Origin and restoration of Masuyama castle

Precise year is unknown but Masuyama castle had been already built in 14th century and at first called as Wadajyo castle. At the beginning of Muromachi era, Naotsune Momoi (?-1376) was appointed as a governor of Ecchu province, but later Naotsune revolted against Muromachi Shogunate thus Shogunate sent their army to subjugate Momotsune. During this battle Wadajyo castle was used by Ninomiya clan, a general of Shogunate army. But after the cease of rebellion Wada castle was once disposed.Over 100 years after that, Masuyama castle was really built by Jinbou (Jinbo) clan. Jinbou clan was originally a retainer of Hatakeyama clan, a traditional and high class retainer of Muromachi Shogunate. Hatakeyama clan originally held the governor of provinces at Kinki region, but was also appointed as the governor of Ecchu province after Momoi clan. But Ecchu province was too distant from Kyoto city, thus Hatakeyama clan placed Yusa clan, Jinbou clan and Shiina clan as deputy governors and let them administrate each area.

Ambition of Jinbou clan for independence

As Hatakeyama clan was a distinguished family and relative of Shogun, they prospered in 15th century as one of three houses which is eligible for Kanrei position (grand minister) of Muromachi Shogunate. But since the end of 15th century, Hatakeyama clan significantly lost their power because of their internal conflict and battle against Hosokawa clan. Hatakeyama clan could not control Ecchu province any more, and Jinbou clan gradually grew their power.In 1493, when Yoshitane Ashikaga (1466-1523), the 10th Shogun of Ashikaga Shogunate, lost his position as a result of conflict with Hosokawa clan, came to Ecchu province to ask support from Jinbou clan. Nagnobu Jinbou (?-1501), the leader of Jinbou clan, protected Yoshitane's government in exiled. Furthermore, Yoshimune Jinbou (?-1521), son of Yoshitane, tried to become independent from Hatakeyama clan in cooperation with Ikko Ikki group, a religious army consists of believers of Ikkoshu, a denomination of Japanese Buddhism. But in 1519, Yoshitane was attacked by Hatakeyama clan and Uesugi clan, the governor of Echigo province (Niigata prefecture) which supported Hatakeyama clan, and once Jinbou clan was extinguished.

Struggle against Kenshin Uesugi and fall

But Nagamoto Jinbou (?-1572), survived son of Yoshitane, restored Jinbou clan utilizing fall of Hatakeyama clan and internal conflict of Uesugi clan. By the middle of 15th century Jinbou clan seized whole Tonami plain, then built Toyama castle and advanced to Toyama plain. Jinbou clan suppressed Shiina clan and seemed to unite Ecchu province. Jinbou clan had castles at Toyama plain and Tonami plain, but as a basement in wartime and connecting point, Masuyama castle was an important base of Jinbou clan.However, after 1550's, Uesugi clan once retreated to Echigo province again seek extension toward Ecchu province. Unfortunately, Kenshin Uesugi (1530-1578), new leader of Uesugi clan, was so brilliant at tactics and called as god of war. In 1559, Kenshin Uesugi intruded into Ecchu province with large army, and Nagamoto disposed Toyama castle and besiege at Masuyama castle. But facing attack of Kenshin, Nagamoto once disposed Masuyama castle and ran away.But just after the return of Kenshin, Nagamoto came back and restored the clan. In 1562 Kenshin attacked Masuyama castle again, and Nagamoto coordinated with Kenshin under meditation of Hatakeyama clan. But finally in 1576, Kenshin who really wanted to seize Ecchu province and already extinguished Shiina clan, captured Masuyama castle and Jinbou clan also ended its history as an independent power.

Seizure by Narimasa Sassa and total reform

Uesugi clan continued expansion toward westward breaking the army of central ruler Nobunaga Oda (1534-1582), and captured Nanao castle (Ishikawa prefecture). But Kenshin died in ill in 1578, and because of their internal conflict for successor Uesugi clan significantly decrease their power. Katsuhie Shibata (1521-1583), the regional commander of Nobunaga, started counter attack toward Uesugi clan and gradually captured Uesugi territory.In 1580, Katsuie already captured Kaga province and Noto province attacked Uesugi army at Ecchu province. In 1581 Oda army attacked Masuyama castle and burned castle town, but this time Masuyama castle barely stood the attack. But finally in 1582, Narimasa Sassa (1536-1588), a general under Katsuie, captured whole part of Ecchu province including Masuyama castle. Narimasa thoroughly reformed Masuyama castle as an important military base at the center of province.

Structure of Masuyama castle

The mountain where Masuyama castle spread over gentle slope toward east from its peak, and east side slope where is the backside of the castle is steep. At the western edge of the mountain there are narrow and unshaped areas such as Umanosego, Ichinomaru and Mujyo, and these areas are thought to be originally built by Jinbou clan.At the east of these old areas, huge and square shaped areas such as Amuro Yashiki or Ninomaru are built. These areas are huge one over 100 meter long, separated by tall clay wall and deep dry moat, and protected by turrets and combined gate. At Sassa period, Ninomaru area at the center of the castle might be used as the main area, and entrance into Ninomaru area is decorated by stone wall. Ahead of these areas there are Sannomaru area and other terraces, and whole part of these areas are surrounded by linear long dry moat, to separate inner area from outer area considering usage of matchlock guns..In addition to these core areas, large terraces such as Goshoyama Yashiki, Ashigaru Yashiki and Ikenotaira Yashiki spreads toward the valley divides the mountain. Furthermore, ahead of the valley where now road passes through, there are another castles such as Kameyama castle or Magotsugiyama fort. Total size of entire castle reaches 1,000 meter long and 500 meter width, and is one of the largest mountain castles in Hokuriku region. At the western hillside opposite of the river castle town spread, and the clay wall separated castle town and castle still remains.

Resistance against Ruler

When Narimasa seized Masuyama castle, his situation was quite unstable. Narimasa originally served for Katusie Shibata, but Katsuie was defeated at the battle of Shizugatake by Hideyoshi Toyotomi (1537-1598) and killed himself at Kitansho Castle in 1583. Narimasa reluctantly served for Hideyoshi, but Narimasa who was originally the direct guard of former ruler Nobunaga Oda (1534-1582) did not like Hideyoshi who was the colleague at Nobunaga. In 1584, when Nobukatsu Oda (1558-1630) and Ieyasu Tokugawa (1543-1616), son and former ally of Nobunaga fight against Hideyoshi, Narimasa belonged to Ieyasu and hostiled to Hideyoshi. Narimasa attacked Suemori castle (Ishikawa prefecture) which was kept by Toshiie Maeda (1538-1599) who belonged to Hideyoshi, but failed to capture it and had to secure his territory. In the meantime Nobukatsu and Ieyasu made peace with Hideyoshi, and Narimasa passed deep snowy Tateyama mountain to persuade Ieyasu to fight against Hideyoshi again, but Ieyasu did not do so any more. Next year in 1585 isolated Narimasa at Toyama castle was attacked by large army of Hideyoshi, thus Narimasa finally surrendered to Hideyoshi. Three years later Hideyoshi appointed Narimasa as a lord of Higo province (Kumamoto prefecture) newly conquered, but Narimasa evoked resistance of local small lords and was forced to die being blamed for the responsibility. Masuyama castle had been used by Maeda clan which held Ecchu province, and was finally abolished around 1610.

Afterward of castle

Now all building is lost but terraces and moats of the castle well remain all over the mountain. Even though not using stone walls except for small part of entrance, but linear line of clay wall and deep moats is exactly the shape of modern castle. Even though not famous, massive clay wall and dry moat equivalent to the castle built by Hojyo clan is worth for seeing. Although this castle is located at heavy snow area, but if visit early spring or late autumn when weeds die with plenty of time, visitors might be able to enjoy this large and skillfully built castle.